The duo performs at the Monty Burns Casino with their tiger Anastasia. Anastasia has a dream about her life in the past and then her eventual capture by Gunter and Ernst (via a tranquillizer dart). Anastasia then goes out of control and attacks them. The duo appears later when Marge gets hypnotized by gambling and Maggie wanders off and runs into Anastasia while Gunter and Ernst are talking to a guy who believes they live in the casino. Barney, however, rescues Maggie from Anastasia and then gives her back to Marge.

Gunter and Ernst were at Springfield airport checking in, but they were told that Anastasia was accidentally sent to East St. Louis.

The pair were among the staff at a Las Vegas casino attempting to stop Homer and Ned from ditching Ginger and Amber. When Homer and Ned are evicted from Las Vegas, Amber and Ginger try to hook up with Gunter and Ernst.

Gunter and Ernst are a parody of Siegfried and Roy, with whom they share several similarities. In a case of fact following fiction, the 1993 episode "$pringfield (Or, How I Learned to Stop Worrying and Love Legalized Gambling)" depicts the duo being savagely mauled by their trademark white tiger, Anastasia. Ten years later, the trained white tiger Montecore dragged Roy Horn offstage by his neck during a performance at The Mirage, severely injuring Horn.